[Xvid-devel] RGBA output images have their alpha values set to 0 (fully transparent)

[delthas]

Hi,

> One reason is that changing the c code (like in your patch) is not
> enough. But there are SIMD assembler versions of the RGB conversion
> functions as well, which also all would have to be changed to be
> consistent.

I could try to patch the assembler versions as well, but this is 
probably not worth the hassle, especially considering your second point:

> And then second, this patch changes the behavior of the xvidcore
> library towards applications. So there may be existing applications
> that rely on xvid_decore to return RGBA images with alpha value 0. So
> this would be a potentially breaking change and could cause certain
> existing programs to not work correctly anymore when linking against a
> new xvidcore library that has this patch applied.

A new field could maybe be added somewhere to specify what behaviour to 
use, by default being the old one, but it's also probably not really 
worth it.

I'll simply write the alpha values back to 255 (full opaque) in my 
library; I agree that it should probably not be merged considering the 
points you made.

For context, I'm creating Go bindings for xvid, they're mostly finished 
now. URL is https://github.com/delthas/go-xvid

Thanks for the quick answers.
-- 
delthas